McBain::WithPSGI turns your McBain API into a RESTful PSGI web service based on
Plack, thus making McBain a web application framework.

The created web service will be a JSON-in JSON-out service. Requests to your
application are expected to have a Content-Type of application/json;
charset=UTF-8. The JSON body of a request will be the payload. The results of
the API will be formatted into JSON as well.